Revisiting Routing Control Platforms with the Eyes and Muscles of Software-Defined Networking

ACM SIGCOMM HotSDN' 12 Workshop

Helsinki, Finland, 13 August 2012

Agenda

• Research in scope and contribution• RouteFlow Control Platform

– Multi-controller architecture– Proof of concept implementation: Single node abstract eBGP router

• Use Cases• Challenges• Conclusions and Future Work

Research in scope and contribution

• Early work on Routing Control Platforms (RCP) [Ramjee 2006, Feamster 2004, Van der Merwe 2006, Wang 2009]– In operation at AT&T, considered a differentiator for "dynamic

connectivity management".

• Research Question: – Re-examine the concept of RCP with the visibility

(i.e., network-wide, multi-layer, flow and topology maps, full RIBs) and direct control capabilities (i.e., actual FIB installation, rich matching and instruction set) of the SDN abstraction set and the specifics of the OpenFlow choice

• RouteFlow glues virtualized IP routing stacks with OpenFlow • RouteFlow acts as a new indirection layer for

– routing protocol messages (e.g. BGP session terminates in servers) – RIB-(to-FIB)-to-OpenFlow transformations

Controller

High costSpecialized config.

Closed sourceSlow innovation

BGP

Low cost (commodity)Multi-vendor modularity

Open sourceRapid innovation

Controller

Open interface

OpenFlow Switches

Open interface

Software Defined IP RoutingOSPF ISIS LDP

Specialized Control Plane

Specialized Hardware

Specialized Features

Controller

Source: McKeown

Controller-Centric Hybrid Networking

• A migration path to roll out OpenFlow technology• Not a revolution, but an evolution of current iBGP RRs to essentially

eBGP Route Controllers– “BGP-free edge”: A cost-effective simplified edge for SW-driven innovations

Design

Key Features• Modular architecture

– RF-Proxy– RF-Server– RF-Client

• Database layer– JSON-based IPC – Resillient core state– Programmer-friendly

• Multi-Controller support– NOX, POX, (Ryu)– Floodlight, Trema (planned)

Modes of operation

• From logical routers (akin VRFs) to single node abstractions over flexible virtual networks.

• New design choices on the distribution of the control nodes.

Aggregated BGP routing service

• Single node abstraction of a domain-wide eBGP router– Think modern multi-chasis routing architectures with external route processors

and OpenFlow switches acting as line cards

• Aggregation logic defined in the RF-Server • NOX, MongoDB, LXC

Routing-centric use cases under research

• Engineered path selection– Think Google WAN, performance-based routing, etc.

• Optimal best path reflection– Per ingress/customer [draft-ietf-idr-bgp-optimal-route-reflection-01]

• Path protection with prefix independent convergence– Hierarchical FIBs w/ OF 1.X Tables + LFA route-precomputation

• Security – Data plane blackholes and middlebox injections,– Secure Inter-domain routing ideas (crypto intense S*-BGP, etc..)

• Simplifying customer multi-homing– Easy to set and control cost/performance/policy-based routing

• IPv6 migration– Flow matching for service termination in v4-v6 migration solutions

Challenges

• Centralized BGP– Shown to scale well in modern CPU architectures– Centralized does not mean not disitrbuted (but removal from edge)

• Small OpenFlow table sizes– Transient limitation?– Expose existing FIB data structures as an IP lookup OF table?– Smart RIB&FIB reduction (e.g., simple [draft-ietf-grow-simple-va-04]– HW/SW flow offloading

• Limited OpenFlow processing in datapath– Transient / Un-optimized implementations

• High availability– Previous ideas from disitributed RCPs– Database-centric designs– Development in-progress of “BGP SHIM” for transparent eBGP redundancy

Conclusions

• RouteFlow is – a simple yet powerful (adaptable, inexpensive) routing architecture– a platform for real IP routing protocol experimentation– a tool for OpenFlow adoption via controller-centric hybrid networking

• Many open research questions and future work– OF 1.X, MPLS, OAM, GUI, policy languages, configuration mgm, etc.

• Opportunity for a community-driven development of competitive, deployable, open routing control solutions

Thank you!

Questions?

Christian Esteve Rothenberg, PhD Diretoria de Redes Convergentes (DRC)

esteve@cpqd.com.br

Live DEMO

• Access: – http://go.cpqd.com.br/7API-demo

• Indiana University GUI demo:– http://goo.gl/T3Tqe

Compare interfaces over the last 30 years

Source: Chris Small (Indiana)

RouteFlow User Interface

• How to make network administration:– Simpler to implement– More robust and consistent– Easier to manage

• Automation and Abstraction• Can you build very different interfaces with SDN backends?E.g., type: http://netkarma.testlab.grnoc.iu.edu/rf/ or... http://goo.gl/T3Tqe

Source: Chris Small (Indiana)

RouteFlow Platform research topics

• High availability• Integration of OF v1.1, v1.2 and v1.3• LDP / MPLS support towards open-source LSR• Realizing the northbound SDN abstractions

– Specification / Configuration– Network Information Base– Knowledge Information Base

• Troubleshooting, testing, debugging, ...• ...

L2 L3 ACL

Collaborations and community developments

• Web-based UI & Internet 2 HW pilot [C. Small, Indiana]• Aggregated BGP Routing Service [C. Corrêa, Unirio]• SNMP plugin [J. Stringer, Google]

• Optimal BGP best path reflection [R. Raszuk, NTT-MCL]• OpenFlow v1.1 and v1.2 [w/ Ericsson]• Open Label Switched Router [OSRF; Google]

• Multi-path, Fast-ReRoute, BGP-Sec, IPv6, ... [YOU?]

✔✔✔

◷◶◵

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http://go.cpqd.com.br/routeflow/

Visits: 12,000+ (5,000+ Unique)From over 1,100 cities of 90+ countries all over the globe!

368days since

Project Launch

… building a community

Conclusions

• RouteFlow is – a simple yet powerful (adaptable, inexpensive) router design– a platform for real routing protocol experimentation– a tool for OpenFlow adoption via controller-centric hybrid networking

• Many open research questions• Experimental research facilities are critical for validation• Opportunity for a community-driven development of

competitive, deployable, open routing control solutions

Beneficios e impactos

• Inovação tecnológica em soluções de redes e serviços para os proprietários de infra-estrutura, os provedores de serviços e a comunidade de pesquisa.

• Oportunidade para que empresas nacionais possam competir e inovar na área de aplicações para gerenciamento e controle de redes de pacotes.

• Novos modelos de negócio que promovem redução de CAPEX e OPEX por meio de novos serviços (ex. alocação dinâmica de fatias/recursos da rede), reaproveitamento de ativos e automatização dos processos operacionais.

• Diminuição do tempo ao mercado na implementação de funcionalidades e soluções de redes integradas e customizadas à demanda do cliente.

• Simplificação e barateamento dos equipamentos pela diminuição dos requisitos mínimos de SW embarcado e pilhas de protocolos proprietárias.

• Consolidação dos planos de controle e gerência de infra-estruturas de rede, facilitando a convergência ampla e a migração para novos padrões e tecnologias de rede de transporte.

Virtualized Data Plane

OF

SDN Converged Network Services

OF

OF

OF

Path, QoS & Security Policies

Transport Plane

RigidLegacy Transport Network

Open Flow-EnabledSoftware Defined Network

Application or Destination-Driven Traffic Optimization

App App...App App...App App...

CS CS

DNS

DNS

CS

Network Monitoring

Rede Convergente Definida por Software (RCDS)

Source: NEC, adapted

Path calcul.Path calcul.

ForwardingForwarding

TCP / IPTCP / IP

Internet

Router

... AppApp

NGN

SDPSDP

App

App

Path calcul.Path calcul.

ForwardingForwarding

SecuritySecurity

QoSQoS

Router

...

SDN

ForwardingForwarding

ForwardingForwardingForwardingForwarding

OpenFlow Switch / Router

Network Operating System

Path calcul.Path calcul. SecuritySecurityQoSQoS

SDPSDP

OpenFlow Server

App

App

App

App

App

App

App

App

App

App

“Modern” OF/SDN architecture

Control Plane Distribution Options